Bug Description

marco@natty:~$ LC_ALL="en_US" sudo apt-get install virtualbox-ose-guest-x11
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
virtualbox-ose-guest-x11 : Depends: xorg-video-abi-8.0 but it is not installableDepends: xserver-xorg-core (>= 2:1.8.99.905-1ubuntu3) but it is not going to be installedDepends: xorg-input-abi-11.0 but it is not installable
E: Broken packages

Checking the VBox' recent code, I saw some updates related to X11; however I don't know if they fix the issue.

Related branches

This will happen sometime soon, but the X.Org Server 1.10 ABI doesn't seem to have settled yet - there were incompatible changes between the most recent release candidate and the (more recent) snapshot that Ubuntu Natty is using.

This experimental Additions build (see [http://www.virtualbox.org/wiki/Testbuilds]) worked for me with a Natty guest updated this morning. It is from the development branch but should work with 4.0. Note though that you will want to disable DPMS in the guest due to a bug in the host code that was fixed after 4.0.2 was released.

Better than disabling DPMS, here are a couple of links to current builds from the stable branch (that is, 4.0.2 plus a few fixes, including the one I mentioned). The links should be valid at least as long as the Additions one above. They are shell script installers, not Debian packages, but won't hurt your system (they put everything into /opt apart from some symbolic links in /usr).